#include<stdio.h>
#include<stdlib.h>
int main() 
{
	int i,j;
	int x=5;
	int y=10;
	int height=20;
	int velocity=1;
	
	while(1){
		x=x+velocity;
		
		system("cls");
		
		for(i=0;i<x;i++){
			printf("\n");
		}
		for(j=0;j<y;j++){
			printf(" ");
		}
		printf("o");
		printf("\n");
		
		if(x==height){
			velocity=-velocity;
		}
		if(x==0){
			velocity=-velocity;
		}
	}
	return 0;
}
